1. Field of the Invention
The present invention relates to a device with capabilities for reading images from documents such as an image communication device or a copier (generically called an image reading device) and, more particularly, to an image reading device using a fixedly mounted contact-type image sensor to read images from documents being fed through the device.
2. Description of the Prior Art
The reading of images from original documents is conventionally accomplished by use of a contact-type image sensor unit integrally comprising a light source for lighting the surface of original documents against a base, a lens arrangement for forming the image reflected from the document surface, and an array of photoelectric transfer elements located in the image-forming position of the lens arrangement. In prior art image communication devices, this type of image sensor unit is fixedly located under the document transport path and faces the downside document surface (i.e. the downwardly facing surface of the document).
One disadvantage of the above-mentioned construction is the difficulty in maintaining the image sensor unit. Because the image sensor unit is incorporated in the central region of the device, cleaning, replacing or otherwise maintaining the unit requires disassembling the parts in the middle of the device, which takes time and effort.